What Are Microservices and How Do They Work?

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Microservices permit developers to compartmentalize a software development project into a collection of modular services. 

The insular nature of microservice architecture can make software development projects easier to build and manage. 

Many major companies such as PayPal, Netflix, and even Amazon utilize microservices, demonstrating that microservices can be a utilitarian asset toward developing a scalable software product. 

To learn more about microservices and how they work, stay tuned. Today, you’ll find out how microservices can be useful for your business. 

What Are Microservices?

Microservices are a means of arranging an application via several independent, single-function protocols or services.

The standard architectural style for building software applications is the monolithic architecture pattern. 

Though for many or most applications, a monolithic architecture is an adequate choice, it does come with its limitations. 

Namely, a monolithic application encourages tight coupling where many of the components of a software system are interconnected. Such a dependency can sometimes be helpful but often it can mean increasing complexity over time. 

And changes to a monolithic application also typically involve negative effects on runtime and processing speed. 

As a result, scalability becomes a looming concern. The interdependency and intricate information flow of monolithic architectures can ultimately be a setback for the software development life cycle and the continued maintenance of your software application. 

On the other hand, microservice architecture is independently deployable. If aptly applied, this platform approach can stimulate business growth by enhancing your software development process. 

With microservices, software components are largely disconnected, allowing for loose coupling. The manipulation of one function does not affect a related function and vice versa. 

The formal definition of microservices varies as many characteristics define its nature. Microservices are generally processes that communicate over a network, self-contained, small in size, etc. 
Likewise, prominent software engineer Martin Fowler defines several principle features that describe microservices and/or their utilization in software development:

  • business capability
  • automated deployment
  • endpoint intelligence
  • decentralized control of languages and data

In short, many of these attributes measure up to the fact that microservices prompt continuous delivery (CD). In agile software development, CD warrants rebuilding and redeploying software in order to optimize the final product.

To add, the microservice architectural pattern is driven by strong service-oriented principles, like domain-driven design (DDD). DDD ensures that software matches up with its business intent. 

How Do Microservices Work?

Microservices work by isolating software functionality into multiple, independent modules that carry singular responsibilities.

An illustration of a mobile device connected to multiple API symbols, representing the concept of API integration in mobile applications.

Due to an ever-increasing demand for large-scale applications, microservices fill a need for a more intentional approach to software development that bodes well with business growth. 

But how do microservices work? While the actual development of an application utilizing microservice architecture is quite complicated, here is a brief overview of the conceptual origins of microservices. 

Monolithic Applications

To better understand how microservice architecture works, you should revisit the concept of monolithic architecture.

The basic construction of a monolithic software application consists of three layers — the presentation element or user interface (UI), the business logic, and the database. 
While front-end development comprises UI building, back-end developers write the business logic and manage the database.

Now, this stack is pretty linear and doesn’t seem in the least bit complicated. But in some ways, the opposite is true. 

There are many points of failure that can occur when only one central system hosts all of the most important bits and pieces of your software application. 

A hardware failure or bug could greatly damage a system with this architecture and it would not be easy to recover from. 

On the server-side of operations, scaling monolithic applications also entails employing new servers to handle the extra bandwidth required and user capacity. Naturally, this leads to an uneven balance of resources. 

Service-Oriented Architecture (SOA)

Service-oriented architecture (SOA) arose from the issues described above. Contextualizing functionality in terms of specific services that modular pieces of code can address leads to more intuitive and autonomous software structures. 

SOA balances services across servers, aggregating them over a network and relying on application programming interfaces (APIs) to decouple services. Load balancing, in turn, becomes more stable and uniform. 

SOA enables shorter development cycles, as small, specialized teams can focus on just one service at a time. 

Microservices

Microservices is a particular type of service-oriented architecture. They break down the concept of service-oriented architecture even further by addressing concerns in a hyper-individualistic fashion. 
Hundreds of microservices combine to extend users a larger macroservice or set of macroservices in the form of a software application. 

Netflix, for example. is well-known in the industry for migrating from a monolithic architecture to a microservice architecture with over 1000 microservices

Much of microservice architecture is cloud-based and uses container technologies, making it easier to decentralize servers. 

The terminology of containers is derived from packaging containers for freight shipping.  

Prior versions of SOA took advantage of virtual machines. Instead, containers package code and its dependencies into a distinctive unit that can be shipped, so to speak, on the cloud. 
You can also design microservices to be self-healing where you can alienate, troubleshoot, and fix problems through automation. Of course, a monolithic application would need too much human intervention for this to work on a mass scale. 

What Are the Main Applications of Microservices?

You can choose to apply microservices to your software architecture for a number of reasons. Below are some examples where microservices would be a good fit. 

Small Teams

Microservice architecture serves as a befitting complement to small software development teams. 

Since software development amounts to building multiple, self-sufficient services, you can hand-pick a few accomplished developers and designate them to a certain service that needs to be built. 
Overall, this mitigates the drain on resources that is inevitable when internal staffing becomes difficult or if you’re working with a limited budget. 

Testing & Deployment

Deploying and testing software that uses microservice architecture is frankly less challenging than doing the same with a monolithic application. 

Of course, testing and debugging a monolithic application requires executing the entirety of your application at once, finding bugs manually, and resolving them in such a way that the resolutions do not negatively impact other parts of your code. 
Developers must make sure to watch out for the latter circumstance as monolithic applications are by definition codependent so every change has the potential to create a butterfly effect. 

Making upgrades and updates to your application can be similarly frustrating for the same reasons. 

These limitations make scalability cumbersome as well, which should be a big concern for virtually any business. 

Diverse Tech Stacks

Using microservices, you will be able to utilize more than one tech stack. For instance, one small team could work on a Python service and the other can use Ruby. 

This gives you more leeway with hiring developers and deciding which programming languages and development tools are best to use. 

A one-size-fits-all approach is convenient for small applications but larger projects usually call for more versatility. In software development, this allows for exploring and using different programming languages, frameworks, databases, and so on. 

6 Characteristics of Microservices

Microservices and their immediate benefits can be broken down into several key characteristics.

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1. Multiple Components

Again, the founding quality of microservice architecture is that a development team structures software into component services. Therefore, services can function independently of each other. 

2. Built for Business

To echo Martin Fowler, microservices center business capability. Compared to monolithic applications, microservices foster efficiency by advancing the effectiveness of small teams.  

3. Simple Routing

Microservices receive requests and respond to them. Simple, right? Well, a monolithic application would activate a train of dependent application layers and functionalities might bump into each other to produce the same end goal. 

4. Decentralized

Data management is decentralized. For fans of microservices, they consider this more secure. 

Reusability is also a by-product of decentralization, as self-contained services solve specific issues. 

5. Failure Resistant

It’s frankly implausible for all the services in a microservices software system to fail at once. One service could fail, surely, but this has no effect whatsoever on its adjacent service. 

6. Evolutionary

Microservices can grow with your business. Adding new functionality happens outside of a monolithic system, easing scalability altogether.  

What Are the Pros and Cons of Microservices?

The pros and cons of microservices are important to consider before making any noteworthy decision on how to go about building your next software project. 

Microservices offer a relatively new methodology for software development. Although the abstraction of application building is exciting, you still need to be critical towards new modes of development, however popular they may be. 

Pros of Microservices

The pros of microservices should be pretty obvious given the main applications of microservice architecture, but perhaps it’s worth it to take a closer look at just what microservices can do. 

Simple

Many aspects of microservice architecture contribute to its simplicity. For one, the intentional distribution of functionality that is core to the fundamentals of microservices means more compact deployments of code

Ergo, writing code per function or service is much more straightforward, and virtually painless when developers do not have to account for function dependencies. 

The scope of a project is smaller than otherwise, thus developers can leverage continuous deployment due to the productivity boost. 

As mentioned above, testing takes advantage of microservice architecture too, since developers can isolate faults quicker. And of course, a quality software product is better done sooner rather than later. 

Scalable

The categorical grouping of functionalities that microservice architecture allows means that you can scale one or a few services when the time is right, and save the work of scaling your entire application. 
By this procedure, you can budget resources adequately, and save costs accordingly. 

Cons of Microservices

The cons of microservices are harder to decipher, especially since the architecture has so many benefits. But there are still some things you should watch out for before deciding to use microservice architecture for your business. 

Demanding

Microservices demand multiple databases and servers and a whole lot of transaction management. 

Indeed, implementing microservice architecture will be a resource-heavy endeavor. In consequence, large companies take to microservices quite well, but small companies struggle to adopt the infrastructure. 

Proper orchestration of microservice architecture is paramount, but given its exhaustive needs, this is a more strenuous task than some businesses are ready for. 

Complex

It might seem odd that complex and simple describe the same concept, but you’ll understand soon. 

Though microservice architecture can simplify the overall development of your application, the services that you create independently do have to meet at some point

Communication between each service can be tough to set up, and you may have to write extra code to ensure each model can connect with one another without error. 

Microservices vs. APIs: What’s the Difference?

The primary difference between microservices and APIs is in their respective functions and classifications. 

For instance, an API defines protocols for integrating two or more software systems. Here are some examples of APIs:

  • Log-in portals that rely on different social networks for you to create or transfer account information as in logging in using your Google account to an unrelated app or website
  • Google pulling information from local online resources when you search for a nearby restaurant or event
  • Youtube videos embedded on a web page other than Youtube itself

Conversely, microservice architecture delineates a particular technique for developing software applications, breaking down functions into freestanding services

Microservices depend on APIs to connect these services, but they are not API themselves. 
Many major companies develop and maintain their software through a microservice architecture, including:

  • eBay
  • SoundCloud
  • Uber
  • Groupon

It’s not clear why microservices and APIs would appear to be similar or equivalent but they have completely different roles in the software development world. 

Conclusion

Microservices or microservice architecture can refine your software development process for the better. Propelled by microservice architecture, developers can mentally and literally create flexible, function-oriented services. 
Service-oriented architecture is generally advantageous for software development, if only conceptually. Whereas monolithic application building falls short in several instances. 
That said, microservices do have their pros and cons, and it’s crucial to be aware of them. 

But if after reading about microservices and their characteristics, you still wish to implement them into your project, Trio can help. 
Trio has qualified software developers available to build your project, your way. Contact Trio now to get started!

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With over 10 years of experience in software outsourcing, Alex has assisted in building high-performance teams before co-founding Trio with his partner Daniel. Today he enjoys helping people hire the best software developers from Latin America and writing great content on how to do that!
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